Leg brace orthopedic appliance



July 5, 1960 K. B. NELSON LEG BRACE ORTHOPEDIC APPLIANCE 2 Sheets-Sheet 1 Filed Oct. 5, 1959 A .N R0 EE V 0 J mm 1 A ml 7 ma B w w WI w l|l o a on; I I O .3; Y M 7m W 4 "w 3 w J rrv ml: wtllLlmilluqr IL. IN.-

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LEG BRACE ORTHOPEDIC APPLIANCE Filed Oct. 5, 1959 2 Sheets-Sheet 2 INVENTOR. 4 027 5 MFA SON BY ATTORNEY United States Patent 2,943,622 LEG BRACE 'ORTHOPEDIC APPLIANCE Kurt B. Nelson, 6112 Station St., Monroeville, Pa. Filed Oct. 5, 1959, Ser. No. 844,537 1 Claim. (Cl. 128-80) I This invention relates to an orthopedic appliance and, 1n particular, to a hinge-joint lock for a leg brace having means controlled by the wearers heel for rendering it effective.

Locks for the hinge joints of leg braces operable by the wearer have been proposed but those with which I am familiar are clumsy, ineffective in operation and generally unsatisfactory. It is accordingly the object of my invention to provide locking means which is positive in action, easily controlled and inexpensive to manufacture.

In a preferred embodiment, I provide one member of a leg brace with a ratchet disc and the other with a pawl cooperating therewith. I also provide a control wire extending downwardly from the joint into a shoe with which the brace is equipped, and fit into the heel of the shoe means for operating the wire by heel pressure.

A complete understanding of the invention may be obtained from the following detailed description which refers to the accompanying drawings illustrating a preferred form of the invention. In the drawings,

Fig. 1 is a side elevation;

Fig. 2 is a partial side elevation to enlarged scale with parts broken away for clearness;

Fig. 3 is an edge view;

Fig. 4 is a view similar to Fig. 2 showing the parts in alternate positions;

Fig. 5 is an enlarged side elevation of the heel operator;

Fig. 6 is a plan view thereof; and

Fig. 7 is a section through the heel operator taken on the plane of line VIIVII of Fig. 6.

Referring now in detail to the drawings, a leg brace 10 is composed of pairs of upper and lower side bars 11 and 12 connected by a hinge joint 13. The upper bars are fitted with the uspal thigh cuifs 14 and the lower bars are pivoted to a shoe 15. The bars are, of course, arranged in pairs in the usual manner. Only the outer 'bars of the two pairs are shown. The inner bars are connected by a plain pivot joint.

Upper bar #11 is fixed to a hinge block 16. A ratchet disc 17 is formed on the lower end of block 16 and is provided with teeth 18 over a limited segment thereof, and a shoulder 19 spaced therefrom, the function of which will appear shortly. The lower bar :12 is fixed to a hinge block 20 which is pivoted to block 16 by a pin 21. One face of block 20 is recessed as at 22 to accommodate a pawl 23 pivotally mounted therein on a pin 24 for engagement with the teeth 18 of ratchet disc 17. A compression spring 25 seated in a socket in block 20 constantly urges the pawl toward engaging position. One end wall 26 of recess 22 afiords an abutment or stop for engagement by shoulder 19, limiting the angular movement of the two bars 11 and 12. A cover plate 26a overlies the adjacent portions of blocks 16 and 20.

A flexible tube 27 extends downwardly along bar '12 and is secured thereto. A control wire 28 passes through the tube, with its upper end extending through a hole in the end of pawl 23 remote from pivot pin 24. The extreme end of the wire is headed so it can exert a pull on the pawl. The lower end of wire 28 is secured to a crank 29 on a heel operator 30. A spring 31 compressed between the crank and the end of tube 27 exerts a constant downward pull on the wire which overcomes the force of spring 25 and normally withdraws the pawl from engagement with the ratchet disc 17.

Heel operator 30 comprises a base plate 32 secured inside the heel of shoe 15 and a tilting plate 33 pivoted thereon by means of spaced bearing studs 34. Crank 29 is part of an arm 35 which extends laterally of plate 33 through a hole in the side of the shoe. A spring plate 36 has its forward edge secured to plate 32. The rear portion of plate 36 overlies the uptilted edge of plate 33 and is therefore effective to turn it downwardly under the pressure of the heel of the wearer of the brace 10 and shoe 15. This turns crank 29 counterclockwise, compressing spring 31 and thus permitting spring 25 to set pawl 23 into operative engagement with the ratchet teeth 18 on disc 17.

The manner in which the device described above functions in use will now be explained. When the wearer of the brace is standing, with heel pressure applied to plate 36, bars 11 and 12 are alined as shown in Fig. 2, shoulder 19 engages abutment 26 and pawl 23 is free to engage teeth '18 under the pressure of spring 25. The hinge joint 13 is thus locked rigidly. When the wearer desires to free the hinge for turning movement as in sitting down, he raises his heel slightly within shoe 15. This permits spring 31 to pull down on control wire 28 whereupon the force of spring 25 is overcome and pawl 23 is disengaged from the ratchet disc 17, permitting angular movement of bar 11 relative to bar 12. When the wearer desires to arise from a sitting position, the weight of his heel raises wire 28 by means of crank 29, permitting re-engagement of the pawl with the ratchet under the force of spring 25. As he rises, therefore, the hinge lock is effective to prevent reverse angular movement of the bars 11 and 12 but permits turning of bar '11 upwardly to vertical position.

It will be apparent from the foregoing that the invention provides a compact, simple joint lock which is progressively effective and yet may be easily released by a slight movement of the wearers foot. A particularly important feature is the fact that the pawl locks the bars in intermediate as well as final positions.

Although I have illustrated and described but a preferred embodiment of the invention, it will be understood that changes in the details thereof may be made without departing from the spirit of the invention as defined by the appended claim.

I claim:

In a leg brace including upper and lower bars pivoted together and a shoe pivoted to the lower end of the lower bar, the combination therewith of a ratchet disc rigid with one of said bars and a pawl pivoted to the other adapted to engage said disc, a heel plate yieldably tiltable in said shoe under the wearers weight, a crank pivoted in said shoe operable by tilting of said plate, -a control wire connected to said pawl and extending downwardly to said crank, a spring tending to seat said pawl against said ratchet, and a spring urging said wire downwardly to unseat the pawl, said crank acting to overcome said last-mentioned spring when weight is applied to said plate.

References Cited in the file of this patent UNITED STATES PATENTS 137,711 Palmer Apr. 8, 1873 302,433 Scott July 22, 1884 688,936 Devol Dec. 17, 1901 2,071,711 Sprouls Feb. 23, 1937 2,512,826 Clark June 27, 1950 2,594,227 Smith Apr. 22, 1952 

